Loans guide · Reviewed 28 August 2026

EMI is the same amortization formula, under a different name.

Equal Monthly Instalment is a fixed payment, but what it's paying for shifts every month — early instalments are interest-heavy, later ones are principal-heavy, even though the number on the bill never changes.

The EMI formula

EMI = P × r × (1+r)^n ÷ ((1+r)^n − 1). P is the principal, r is the monthly rate (annual rate ÷ 12), and n is the total number of instalments. The formula returns one fixed payment amount that, charged every month against a shrinking balance, brings the loan to zero exactly at the final instalment.

This is identical to the amortization formula used for mortgages and installment loans anywhere in the world — EMI describes how the concept is commonly labeled, not a distinct calculation method.

Why the composition of each EMI changes

Interest is charged only against whatever principal remains outstanding at the start of each period. When the balance is high — near the start of the loan — a larger share of the fixed EMI is consumed by interest, leaving less to reduce principal. As principal drops with each payment, the interest charge on the next period shrinks too, so a growing share of the same fixed EMI goes toward principal. The instalment amount stays constant; the split behind it moves every month.

What the EMI calculator computes

Enter the principal, the annual interest rate, and the number of instalments. The calculator returns the fixed EMI, the total amount repaid across all instalments, and the total interest — the difference between what's borrowed and what's ultimately repaid.

Calculate your EMI ↗ See the full principal-vs-interest schedule ↗

Frequently asked questions

What does EMI stand for?

Equal Monthly Instalment — a term used mainly in South Asian and some other lending markets for what's elsewhere called a fixed loan or amortized payment. It refers to the same fixed, recurring payment used to repay a loan over a set term.

What is the EMI formula?

EMI = P × r × (1+r)^n ÷ ((1+r)^n − 1), where P is the principal borrowed, r is the monthly interest rate (annual rate ÷ 12), and n is the number of monthly instalments. This is the same amortization formula used for mortgages and personal loans worldwide — EMI is a naming convention, not a different calculation.

Why does the interest portion of my EMI shrink over time if the EMI itself is fixed?

Interest is charged only on the remaining balance. Early on, the balance is largest, so a bigger share of each fixed EMI goes to interest. As the balance shrinks with every payment, less interest accrues, so a growing share of the same fixed EMI goes to reducing principal.

Does a lower EMI always mean a cheaper loan?

No. A lower EMI usually comes from a longer term, which spreads the same principal over more interest-accruing months — often increasing total interest paid even though each individual instalment is smaller.

Can I reduce total interest without changing my EMI?

Yes, by making additional principal payments beyond your scheduled EMI when your loan allows it. Extra principal reduces the balance interest is calculated on, which shortens the payoff timeline and lowers total interest paid, without changing the required EMI amount.

Source note: This guide describes the standard EMI/amortization formula as a general illustration. All calculations happen in your browser — nothing you enter is sent to a server or stored. This is educational information, not lending advice.